Coupling element for slide fasteners

ABSTRACT

A coupling element for a slide fastener consists of a strip of thermoplastic synthetic resin material bent or folded about a longitudinal axis into a U-section or J-section so that a wide leg directly overlies a narrow leg and overhangs the latter to form a guiding edge of the slider. The bight of the folded strip is provided with spaced-apart coupling formations or heads matingly engageable with the heads of the opposing coupling element in a slide-fastener stringer. Openings in the strip are provided to clear a needle which serves to stitch the coupling element to a support tape or directly onto the fabric of the garment, while formations around these openings on the underside of the folded strip engage the fabric to prevent shifting of the coupling element relative to the fabric.

O United States Patent 51 3,704,490 Hansen [45] Dec. 5, 1972 54] COUPLING ELEMENT FOR SLIDE FOREIGN PATENTS OR APPLICATIONS FASTENERS 871,458 6/1961 Great Britain ..24/205.l3 D [72] Inventor: Harry Hansen, Copenhagen, Valby, 1,285,599 1/1962 France ..24/205.13 D

Denmark Primary Examiner-Bernard A. Gelak [73] Assignee: Opti-Holdmg AG, Glarus, Switzer- Attomey Kar1F Ross land [22 Filed: Oct. 12, 1971 [57] ABSTRACT [21] AppL NO: 188,334 A coupling element for a slide fastener consists of a strip of thermoplastic synthetic resin material bent or folded about a longitudinal axis into a U-section or J- [30] Foreign Application Priority Data section so that a wide leg directly overlies a narrow leg and overhangs the latter to form a guiding edge of the Oct. 14, 1970 Germany ..P 20 50 438.5 Slider The bight of the folded Strip is provided with Jan. 20, Germany paced apart coupling formations or heads engageable with the heads of the opposing coupling [52] US. Cl 24/205.1, 24/205.l3 D element in a slide-fastener stringer. Openings in the [51] Int. Cl. ..A44b 19/14, A44b 19/34 strip are provided to clear a needle which serves to [58] Field of Search ..24/205.13 D, 205.1, 205.12 stitch the coupling element to a pp p or directly onto the fabric of the garment, while forma- [56] References Cited tions around these openings on the underside of the folded strip engage the fabric to prevent shifting of the UNITED STATES PATENTS coupling element relative to the fabric.

2,772,469 12/1956 Staller ..24/205.13 D 10 Claims, 10 Drawing Figures PATENTEDuEc 5|s72 3 704 4% sum 1 or 5 1 log [q w 90 Lg b 2 INVENTORI Har y Han en By 12m PATENTEDBEE 19R 3.704.490

sum 2 BF 5 Attorney PATENTED DEC 5 I972 PATENTED DEC 5 m2 SHEET 5 OF 5 I NVEN Harry Ha COUPLING ELEMENT FOR SLIDE FASTENERS CROSS-REFERENCE TO COPENDING APPLICATION The present application relates to my application Ser. No. 184,056 filed Sept. 27, l97l which discloses a coupling element for a slide fastener structurally related to the subject of the present invention.

1. Field of the Invention My present invention relates to slide fasteners and, more particularly, to an improved coupling element for a slide fastener.

2. Background of the lnvention In the slide-fastener art, a coupling element is defined as the member provided along one edge of a support tape or a fabric (e.g., a garment) upon which the slide fastener is provided, for mating engagement with a complementary coupling element of the other slide-fastener half upon movement of a slider along the coupling elements. The slidefastener half may thus consist of the aforementioned support tape or the supporting layer of fabric and the coupling element. In a slide fastener of the nonseparable type, end-stop members are formed at each end of the slide fastener to prevent withdrawal of the slider and separation of the two halves of the fastener. In separable slide fasteners, one or each end of the slide fastener may have a pair of interfittable end-stop members designed to allow one coupling element to be fed into the slider and to be aligned with the other coupling element when the fastener is to be closed. Coupling elements may be of the continuous or discontinuous type, depending upon whether the coupling heads or formations are unitarily formed in longitudinally spaced relationship upon a single element or are individual bodies clamped to the supporting layer. The present invention is concerned with a continuous coupling element.

It has been proposed heretofore to provide continuous coupling elements in the form of molded syntheticresin strips having heads in longitudinally spaced relationship along an edge and separated by spaces of a configuration complementary to the heads so that the heads of the mating coupling element are received between, and engage behind, the heads of the other coupling element. These heads may project through openings in a fabric or material overlying the support layer, the coupling element being attached thereto by stitching around shanks upon which the heads are formed. Similar attachment methods are used with helicoidal coupling elements and meandering coupling elements made from synthetic-resin monofilament strands.

All of these systems have the disadvantage that they are readily deformable by the stresses applied to the coupling element, are insufficiently stable in a dimensioned sense so that they cannot be used for small interhead spacing, or are expensive to manufacture and mount upon the support layer. It has been proposed more recently to provide a coupling element in the form of a bent strip in which the fabric is received between the legs of the bent. As in the earlier systems, this arrangement has the disadvantage that the slider must engage either the supporting fabric layer or the threads used to mount the coupling element. Furthermore, the latter system is relatively thick and hence cannot be used for fine tailoring applications and is not amenable to use as an invisible or concealed coupling element. It should be noted that an invisible or concealed slide fastener is one which is provided on the reverse face of a fabric exposed to view and can be engaged without exposure through a gap between the fabric lips definingthe opening to be closed by the fastener. The strip-type slide fastener suffers from certain lacks of dimensional stability and stress resistance and is also difficult or expensive to manufacture.

OBJECTS OF THE INVENTION It is the principal object of the present invention to provide an improved slide fastener adapted to obviate the aforementioned disadvantages.

It is another object of the invention to provide a coupling element for an improved slide fastener which is of simple manufacture and is easily mounted upon a support tape or directly upon the fabric of a garment, which is inexpensive, which is dimensionally stable and highly resistant to stress but of sufficient flexibility in the coupling plane, and which can be made of a suitable fineness or small gauge.

Still another object of the invention is to provide a coupling element which, in spite of increased fineness and reduced interhead spacing, is highly resistant to breakage under all of the stresses arising in the use of the slide fastener.

Still further, it is an object of the invention to provide a coupling element for the purposes described which is particularly suitable for use in a concealed or invisible slide fastener and which is free from the wear of the fabric or attachment threads characterizing earlier systems.

SUMMARY OF THE INVENTION.

These objects and others which will become ap parent hereinafter, are attained in accordance with the present invention, with a coupling element for a slide fastener in the form of a coninuous synthetic-resin strip folded about a longitudinal axis so as to form a relatively wide outer flange directly overlying and in face-toface engagement with a relatively narrow inner flange or leg attached to overlie the support layer to which the strip is secured. According to the invention, the bight of the strip is provided with spacedapart coupling formations engageable with the coupling formations of a like coupling element while the strip is formed, between a slider-guide edge defined by the overhang and the heads, with a row of longitudinally spaced needle-passing openings or windows, into which the stitching needle may pass in securing the coupling element to the support. In the region of these windows and at least on two opposite sides thereof, I provide projections from the underside of the strip engageable with the fabric layer to prevent shifting of the strip relative to the support layer.

According to an essential feature of the present invention, the folded synthetic-resin strip having two superimposed flanges, legs or bands, is secured to one side only of the support and is provided, along its face turned toward the support, with anchoring projections in the region of the stitching openings or windows for limiting relative movement of the support layer and the strip while the edge of the strip turned away from the coupling formations forms a slider-guiding flange which is spaced from the fabric by the underturned nar row leg.

These features of the invention ensure a limited overall height or thickness of the slide fastener and increase its resistance to stress, wear and breakdown. The fact that a slider-guide flange is provided continuously along each of the coupling elements and is spaced above the fabric, allows the slider to have an underhanging ledge and, therefore, to be relatively secure although simple and small. By avoiding a fabric between the legs of the folded strip, the height of the slide fastener is reduced while the direct contact between the inner and outer legs ensures greater transverse strength. The openings in the strip permit a direct fastening of the coupling elements to the support fabric, e.g., a garment, or an indirect attachment when, for example, the coupling element is mounted upon a support tape which, in turn, is affixed to the garment. In either case, the slider does not engage the fabric so that this source of wear and binding is avoided and, especially when the threads are wholly or partially sunk beneath the exposed surface of the coupling element, the tendency toward wear of the attachment threads is reduced or eliminated. The anchoring formations in'the region of the needle windows or openings not only prevent shifting of the coupling element relative to the support layer, but reinforce the stitching in preventing longitudinal elongation or contraction and hence maintain the gauge or interhead spacing. By limiting lateral movement, they also prevent or limit the tendency toward binding. The slide fastener described has been found to be highly advantageous for use as an invisible or concealed slide fastener which is directly secured to the fabric of the garment, e.g., to close the slit in skirts, trousers, or the like.

According to another feature of the invention, the needle windows are disposed between the female coupling formations and in line with the coupling heads although it has been found advantageous where greater flexibility in the coupling plane is desired, to orient the openings alongside the female coupling formations and to interrupt the web of thermoplastic synthetic-resin materialbetween the needle window and the female formation. Furthermore, boththe coupling heads and the intervening female formations or cavities are formed in the flat strip, preferably prior to folding, together with holes which are brought into registry when the legs are folded into superimposed relationship.

According to still another feature of the invention, the needle-passing windows of the strip are formed with inwardly convergent or outwardly divergent funnel-like surfaces which guide the needle relative to the coupling element in the event some dislocation may occur during the stitching operation. Between the needle-guide openings, 1 form the exposed surface of the coupling element with a channel in which the attachment threads may lie to minimize the extent, if any, to which the threads may project above this surface and engage the slider.

According to still another feature of the invention, the edges of the legs turned away from the coupling formations'are provided with mutually interlocking formations increasing the stability of the overhanging ledge. These formations may have a Z-configuration so that the formations of the upper (outer) and lower (inner) legs overhang one another.

DESCRIPTION OF THE DRAWING The above and other objects, features and advantages of the present invention will become more readily apparent from the following description, reference being made to the accompanying drawing in which:

FIG. 1 is an enlarged perspective view of a slide fastener embodying the present invention;

FIGS. 1A-1C are detail views illustrating features of the coupling element;

FIG. 2 is a perspective view of the coupling element of FIG. 1 drawn to a still larger scale;

FIG. 3 is a plan view of a coupling element according to another embodiment of theinvention;

FIG. 4 is a cross-sectional view taken along the line IV-IV of FIG. 3;

FIG. 5 is a plan view illustrating still another embodiment of a coupling element according to the invention;

FIG. 6 is a cross-sectional view taken along the line VI-\ I of FIG. 5; and

FIG. 7 is a cross-sectional view VII-VII of FIG. 5.

SPECIFICVDESCRIPTION In FIG. 1, I have shown a thermoplastic syntheticresin slide-fastener stringer 100, consisting of slidefastener halves 101, 102, each having a couplingelement 3 extending continuously along an edge of an opening to be closed along the side thereof opposite the face 103 to be exposed. The coupling elements 3 are intended to be brought into engagement or disengagement by a slider 2 movable in the direction of arrow 104 and having a tongue (not shown) reaching through the gap 105 between the fabric layers 6 or on the concealed side of the layers to which the coupling elements 3 are secured. I 1

As can be seen from FIG. 1A, the couplings 3 can be formed from an injection-molded strip 106 of synthetic resin provided with frustoconical openings 107 connected by V-section channels 108, openings 109 attached to constitute the female connecting formations and openings 110 alignable with the openings 107 to form the needle-receiving windows to be described in greater detail. While anchoring formations running in the longitudinal direction have been shown in FIGS. 1 and 2, it should be understood that individual sets of formations 111 can also be provided about each opening 110. The strip is folded about the longitudinal axis F to form a bight portion B which is provided with coupling heads 1 with intervening female formations.

Both coupling elements 3 are thus bent in a U-configuration forming a thermoplastic extruded or injection-molded strip by a bending action which simultaneously forms the coupling heads. In the systems of FIGS. 1 and 2, the heads are shown to be provided with lateral projections 4 which form seats 4' preventing transfer separation of the interlocked coupling elements in the direction of arrow T. The folded coupling element comprises an inner relatively narrow leg 112 and an overlying relatively wide leg 113 connected by the bight 114 (FIG. 2) and a face-to-face contact at 115. The wide leg overhangs the fabric 6 beyond the narrow taken along the line leg to form the slider-guide flange 5. The slider, in turn, is formed with an underturned ledge 5a engaging beneath the flange 5. The slider is thus held above the fabric 6 and is shiftable along the coupling elements without engagement with the fabric.

At longitudinally spaced intervals, the aligned openings 107, 110 form circular windows 7, through which the stitching needle is designed to pass, the opening 7 being provided with inwardly converging or outwardly diverging frustoconical guide surfaces 8 centering the needle with respect to the coupling element when the coupling element may be misoriented in its feed through the sewing machine. Between the openings 7, 8, the upper surface of the coupling elements is channeled with a V-section groove 9 adapted to receive the fastening threads 10 which thus lie below the exposed surface of the coupling element. On the underside of the narrow leg 112, I provide a pair of ridges 11 which flank the openings 7, 8 and are beveled to form edges adapted to penetrate the support fabric. Thus, while continuous extruded ridges provide the anchoring formations in FIGS. 1 and 2, circular ridges lll perform this function in the system of FIG. 1A. The ridges 211 of FIG. 1B are provided in pairs for each opening 207 in the modification of FIG. 1B,

whereas the anchoring formations are provided in the form of diametrically opposite pins 311 in the embodiment of FIG. 1C.

In the system of FIGS. 3 and 4, the coupling heads 1' differ from those of FIGS. 1 and 2 in that the lateral formations 4' are molded in the heads and engage shoulders 4a formed by folding of the strip. In this case, the projections 11' are provided on opposite sides of the openings 7, 8', but lie within the outlines of these openings. The window 7 opens in the direction of the head-receiving recess R and the synthetic-resin web between them is omitted at W to increase the flexibility of the coupling element in the coupling plane. The windows 7', 8' (the latter being funnel-shaped as described earlier) are of rectangular or square outline and have their diagonals aligned in the longitudinal direction of the slide fastener. The coupling element 3', moreover, is provided with a channel 9' between the windows and with an overhanging ledge 5' forming a guide for the slider.

In the embodiment of FIGS. 5-7, in which the coupling heads 1', the thread-receiving channel 9, the windows 7' and the beveled guide surfaces 8 are constructed in the manner described in connection with FIGS. 3 and 4, the lower leg 12 is formed with the regions 11 as already described. The lower and upper legs 12 and 13 are formed with overlapping Z-shaped tails l4 and 15, respectively, which lie in formfitting relationship (see FIGS. 5 and 7) to define the guide flange 5" of the coupling elements. The legs of the Zs fit into one another and hence support one another against transverse stress.

The improvement described and illustrated is believed to admit of many modifications within the ability of persons skilled in the art, all such modifications being considered within the spirit and scope of the invention except as limited by the appended claims.

Iclaim:

1. In a slide fastener having a support layer, the improvement which comprises a couplin element overlymg a surface of said layer and II'ICIU mg a continuous synthetic-resin strip folded about a longitudinal axis to form a relatively narrow leg engaging said layer and a relatively wide leg overlying said narrow leg and joined thereto along a bight of said strip; a multiplicity of coupling formations formed along said bight in longitudinally equispaced relationship for interengagement with corresponding coupling formations of a mating coupling element; a slider guide flange formed by a portion of said wide leg overhanging said narrow leg on a side of said strip opposite said bight, said strip being formed inwardly of said bight with a row of longitudinally spaced needle-passing openings; anchoring formations provided on said narrow leg in the region of said window and engaging said layer for limiting relative displacement of said layer and said coupling element; and a row of stitching fastening said coupling element to said layer and passing through said window.

' 2. The improvement defined in claim 1, further comprising a channel formed in said wide leg between said windows and receiving said stitching.

3. The improvement defined in claim 2 wherein said windows have outwardly divergent flanks for guiding a needle into said windows.

4. The improvement defined in claim 3 wherein said anchoring formations are rows of beveled ridges defining edges on opposite sides of said windows.

5. The improvement defined in claim 1 wherein said coupling formations include coupling heads and recesses complementary to said heads and formed in said strip between them, said windows opening into said recesses.

6. The improvement defined in claim 1 wherein said windows are of generally rectangular configuration and are aligned along their diagonals in the longitudinal direction of the coupling element.

7. The improvement defined in claim 1 wherein said wide and narrow legs are provided with formfitting members remote from said bight and defining said guide flange.

8. The improvement defined in claim 7 wherein said formfitting members are of generally Z-shape.

9. The improvement defined in claim 1 wherein said coupling element is composed of a thermoplastic extrudable or moldable material.

10. The improvement defined in claim 1, further comprising a slider having a ledge engageable beneath said flange.

unrnnn rmnn 

1. In a slide fastener having a support layer, the improvement which comprises a coupling element overlying a surface of said layer and including a continuous synthetic-resin strip folded about a longitudinal axis to form a relatively narrow leg engaging said layer and a relatively wide leg overlying said narrow leg and joined thereto along a bight of said strip; a multiplicity of coupling formations formed along said bight in longitudinally equispaced relationship for interengagement with corresponding coupling formations of a mating coupling element; a slider guide flange formed by a portion of said wide leg overhanging said narrow leg on a side of said strip opposite said bight, said strip being formed inwardly of said bight with a row of longitudinally spaced needle-passing openings; anchoring formations provided on said narrow leg in the region of said window and engaging said layer for limiting relative displacement of said layer and said coupling element; and a row of stitching fastening said coupling element to said layer and passing through said window.
 2. The improvement defined in claim 1, further comprising a channel formed in said wide leg between said windows and receiving said stitching.
 3. The improvement defined in claim 2 wherein said windows have outwardly divergent flanks for guiding a needle into said windows.
 4. The improvement defined in claim 3 wherein said anchoring formations are rows of beveled ridges defining edges on opposite sides of said windows.
 5. The improvement defined in claim 1 wherein said coupling formations include coupling heads and recesses complementary to said heads and formed in said strip between them, said windows opening into said recesses.
 6. The improvement defined in claim 1 wherein said windows are of generally rectangular configuration and are aligned along their diagonals in the longitudinal direction of the coupling element.
 7. The improvement defined in claim 1 wherein said wide and narrow legs are provided with formfitting members remote from said bight and defining said guide flange.
 8. The improvement defined in claim 7 wherein said formfitting members are of generally Z-shape.
 9. The improvement defined in claim 1 wherein said coupling element is composed of a thermoplastic extrudable or moldable material.
 10. The improvement defined in claim 1, further comprising a slider having a ledge engageable beneath said flange. 